1. Field of the Invention
This invention relates to a conical roller bearing, and more particularly to an improved conical roller bearing which may be used at a location of a support shaft which is subject to deflection (tilting) when the bearing is rotated under a load.
2. Description of the Prior Art
To provide a great load capacity and prevent skewing of rollers during their rotation, conical roller bearings have generally been constructed as shown in FIG. 1 of the accompanying drawings, wherein the extension of the tapered raceway 11a of an inner race 1a, the extension of the tapered raceway 21a of an outer race 2a and the axis passing through the center of a roller 3a are in accord with one another at a point Pa on the axis passing through the center of the roller.
However, where such conventional bearings are used, for example, as the support bearings for the semi-floating rear axle of a motor vehicle as shown in FIG. 2, a load W imparted to the bearing (including the dead weight of the vehicle body and a load) causes the axle 4a to be tilted by an angle Oa with respect to the horizontal axis (this angle being of the order of 10 to 20 minutes for flat road conditions at 15 to 45 minutes when cornering), and this in turn tends to force the bearing to follow such tilting of the axle. Therefore, a roller 3a which is then within the main-load-zone (upper side in the drawing) is subject to a great magnitude of force (edge load) in the smaller-diametered side wall portion thereof while a roller which is then within the sub-load-zone (lower side in the drawing) is subject to moment and thrust loads as the result of the above-described tilting of the axle 4a.
For the prevention of such edge load, it has generally been customary to apply a large crowning to the rollers of the bearing, the inner race 1a or the outer race 2a, to thereby alleviate the effect of the edge load. However, the amount of the crowning available for this purpose was rather limited in relation to the load capacity, and more specifically, a maximum of 5 minutes or so has only been allowed for the tilting of the axle 4a. Thus, the bearing has followed the tilting of the axle 4a which is within the aforesaid range of angle, so that prevention of the edge load has been impossible and in addition, the load capacity has been reduced.